Effect Of Sustained Release On The Antimicrobial Behavior Of Essential Oil Microcapsules

The research and development of natural antimicrobial agents has always been a hot spot of concern.As a kind of natural extract,plant essential oil is an important material for the development of natural antimicrobial agents,but the special physical and chemical properties of plant essential oils affect its application value.As a kind of embedding technology,microcapsule technology can effectively solve many problems in the use of essential oils of plants,but there are relatively few studies on the antimicrobial properties of essential oils for sustained release after microencapsulation.This topic uses 6 plant essential oils(cinnamon,clove,lemongrass,litsea cubeba,oregano and cumin essential oil)and their main components(cinnamaldehyde,eugenol,citronellol,citral,carvacrol and anisene).In order to screen the target,seven common microorganisms(Escherichia coli,Staphylococcus aureus,Candida albicans,Aspergillus niger,Penicillium marjoram,Penicillium expansum,Botrytis cinerea)were used as test strains to screen out the antibacterial The oil with the best performance and the most sensitive test strains were then microencapsulated into the selected essential oils to study the inhibitory properties of the essential oils after microencapsulation and the fumigation method,and the kinetic equation was based on the volatilization curve.The release kinetics of essential oils after microencapsulation of essential oils.The research results are as follows:1.Direct contact screening experiments showed that the six essential oils and their main antimicrobial components can inhibit the growth of the tested strains,except for the bacteriostatic performance of cumin essential oil and its main components and citral(10mm>diameter).In addition,other essential oils and their main components have certain antibacterial properties(20 mm> diameter > 10 mm);2.fumigation screening results show that Botrytis cinerea is not sensitive to the six plant essential oils and its main components(no inhibition zone),mold is more susceptible to inhibition by plant essential oils than bacteria and yeast;Aspergillus niger is more than the Italian Penicillium and expansion for Penicillium,the diameter of the inhibition zone is larger than that of Penicillium and Penicillium spp.,and cinnamaldehyde has the largest inhibition zone diameter(30.33 ± 2.52 mm)for A.niger;3.The direct contact of essential oil microcapsules with MIC and MFC results showed that clove oil and eugenol improved the antimicrobial performance after microencapsulation.The microencapsulation of cinnamon essential oil and cinnamaldehyde reduced the originalantibacterial or bactericidal ability;The mechanism study of the morphology of Aspergillus cells found that microencapsulated clove oil and eugenol increased the permeability and destructiveness of A.niger cell membrane;4.The essential oil microencapsulation fumigation MIC experiment showed that the microencapsulation of clove oil reduced the antibacterial performance of fumigation,and the antimicrobial properties of eugenol did't affect its original antibacterial performance;the effect of sustained release time on the antimicrobial properties of essential oil microcapsules The results show that microencapsulation can effectively enhance the inhibition time;5.By measuring the volatilization curve of essential oil microcapsules and fitting the kinetic equation,it is found that the fitting results of the volatilization curves of clove oil microcapsules and eugenol microcapsules at 50 and 80 °C are more in line with the first-order kinetic equation.The 25 °C and lower microcapsules are more consistent with the Peppas equation;according to the value of n in the Peppas equation,the oil release mechanism in the microcapsules is non-fickian diffusion.